Synthesis and luminescence properties of LiBaPO4:Bi3+ yellow-emitting phosphor for solid-state lighting

Novel LiBaPO₄:Bi³⁺ yellow-emitting phosphor is synthesized by high temperature solid-state reaction method in air. With excitation 260 nm, LiBaPO₄:Bi³⁺ phosphor emits yellow light with the chromaticity coordinate (0.4272, 0.4657) and color rendering index 77.7. Emission band peaking at ~?588 nm of LiBaPO₄:Bi³⁺ phosphor in the range of 400–790 nm is attributed to the ³P₁ → ¹S₀ electron transition of Bi³⁺ ion. Excitation band monitored at 588 nm in the range of 220–300 nm is assigned to the ¹S₀ → ³P₁ electron transition of Bi³⁺ ion. The optimal Bi³⁺ ion concentration in LiBaPO₄:Bi³⁺ phosphor is ~?1.0 mol%. Time resolved spectra and fluorescence lifetime data confirm that there is only Bi³⁺ ion luminous center in LiBaPO₄:Bi³⁺ phosphor. The luminous mechanism is analyzed by configurational coordinate diagram of Bi³⁺ ion. The experiment results are helpful to develop other new Bi³⁺-doped optical materials for solid-state lighting.